GENERAL PURPOSE: To investigate schizophrenic-normal differences in autonomic nervous system activity in various laboratory situations which differ in the demands placed on the subject, the kinds of stimuli presented and the type of behavior required. Peripheral measures of autonomic functioning: Skin conductance, heart rate, finger pulse volume, respiration and skin temperature are recorded continuously during periods of resting, presentation of mild tones and task performance. The tasks used include reaction time, mental arithmetic, two-flash threshold, and tachistoscopic recognition. Drug free acute schizophrenic patients and normal controls have been tested soon after admission to the Clinical Center, just before discharge (3 to 4 months later) and at 1 year follow-up. The autonomic data are being evaluated with respect to diagnosis, outcome, and relationships to task performance, psychiatric condition and biochemical variables. In addition, the normal subjects have been given personality and interest questionnaires.